From: Nick Piggin <nickpiggin@yahoo.com.au>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: wd@denx.de, dzu@denx.de, miltonm@bga.com,
linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org,
Al Viro <viro@zeniv.linux.org.uk>,
Geert.Uytterhoeven@sonycom.com, yanok@emcraft.com
Subject: Re: [PATCH][v2] fork_init: fix division by zero
Date: Fri, 12 Dec 2008 13:36:02 +1000 [thread overview]
Message-ID: <200812121436.03177.nickpiggin@yahoo.com.au> (raw)
In-Reply-To: <20081211184753.97d0db7a.akpm@linux-foundation.org>
On Friday 12 December 2008 13:47, Andrew Morton wrote:
> On Fri, 12 Dec 2008 12:31:33 +1000 Nick Piggin <nickpiggin@yahoo.com.au>
wrote:
> > On Friday 12 December 2008 07:43, Andrew Morton wrote:
> > > On Thu, 11 Dec 2008 20:28:00 +0000
> > >
> > > > Do they actually cross the page boundaries?
> > >
> > > Some flavours of slab have at times done an order-1 allocation for
> > > objects which would fit into an order-0 page (etc) if it looks like
> > > that will be beneficial from a packing POV. I'm unsure whether that
> > > still happens - I tried to get it stamped out for reliability reasons.
> >
> > Hmph, SLUB uses order-3 allocations for 832 byte sized objects
> > by default here (mm struct).
>
> That sucks, but at least it's <= PAGE_ALLOC_COSTLY_ORDER.
Which is somewhat arbitrary a value. order-1 is costly compared to
order-0...
After running my system here for a while and doing various things
with it, I have the ability to allocate 898 order-0 pages (3592K),
or 36 order-3 pages (1152K).
Not as bad as I expected, but the system's only been up for an hour,
and not exactly doing anything unusual (and it has nearly 30MB free,
out of 4GB).
> It's fortunate that everyone has more than 128GB of memory.
And that SLAB still works quite well :)
next prev parent reply other threads:[~2008-12-12 3:36 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-10 16:50 [PATCH][v2] fork_init: fix division by zero Yuri Tikhonov
2008-12-11 20:16 ` Andrew Morton
2008-12-11 20:28 ` Al Viro
2008-12-11 20:43 ` Andrew Morton
2008-12-12 2:31 ` Nick Piggin
2008-12-12 2:47 ` Andrew Morton
2008-12-12 3:36 ` Nick Piggin [this message]
2008-12-11 22:22 ` Re[2]: " Yuri Tikhonov
2008-12-11 22:26 ` Andrew Morton
2008-12-12 0:48 ` Paul Mackerras
2008-12-12 1:07 ` Andrew Morton
2008-12-18 7:47 ` Yuri Tikhonov
2008-12-18 22:45 ` Andrew Morton
2008-12-19 5:49 ` Re[2]: " Yuri Tikhonov
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